When the PV&T started to plan on turning off the SLR’s third rail and replacing it with 3kvdc overhead wire, they (obviously) needed to assign different power to replace the increasingly overworked 1000s & 1100s which were currently hauling freight on the railroad. There wasn’t much spare power on the railroad, so GE was approached for some new electrics.

GE had recently manufactured a small fleet of E10Bs for the Niagara Junction, so suggested something like that, but with the proper voltage for the PV&T’s electrification. The Niagara Junction was close enough so that the engineering department could send people out to inspect the units and see how they worked on a switching railroad, and they proved to be a perfectly cromulent choice for the SLR’s needs.

So the SLR ordered 8 of them to replace 9 of the existing 1000s & 1100s. About twice the horsepower and twice the weight, so instead of 10 little locomotives working all the time to haul increasing freight loads it became 8 larger locomotives working part of the time to haul the same loads and have a couple of spare locomotives so that the local switching on the PV&T line into Boston could be transferred over to the SLR.

The fleet operated unchanged until 1999, when Amtrak’s electrification of the Boston end of the NE corridor cut off the Quincy running track. 325 was taken out of service at that point (sent to the historical fleet in Saint-Constant), then 323 & 326 were reassigned to the ORRC in 2005 & 2008 respectively, 324 & 327 were retired in 2010 & 2020 respectively, and the final 3 (320-322) went to the CSS&SB – and then the TdM for operations on the Montréal-Est industrial district – when the bulk of the SLR was reenergized at 25kvac and new class JSes & M2s were brought in to handle freight.